Percussion tool



Feb. 24, 1948. v, Q 2,436,450

PERCUSS ION TOOL Filed Oct. 24, 1942 2 Sheets-Sheet 1 Fl 1.. FI E .5 75 f (if /5 INVEN TOR. Var/70v? A Pr/ce ATTOZA/[Kl Patented Feb. 24, .1948

p, UNITED STATES 2,436,450 rnnoussron TOOL Vernon L. Price, San Jose, Calif.

Application October 24, 1942, seriarnaasazis 2 Claims.

This invention relates to percussion tools and more particularly to cradle or shell mounted type. In general, these devices utilize a fluid actuated percussive tool, within which a hammer nection between handle or grip means and the tool to be driven whereby the vibration may be dissipated instead of transmitted to the operator.

Additionally, it is an object of the invention to provide a device in which a positive grip is maintained on the bit or other tool while utilizing a floating hammer means.

" These and other objects of the invention will become more apparent as this specification prceeds and the novelty of the invention will be "pointed out with the requisite degree of particularity in the appended claims.

In the drawings forming a part hereof wherein three preferred embodiments of the invention are shown:

Figure l is a front elevation of a percussion tool,

Figure 2 is a side elevation of the subject-matter of Figure 1,

Figure 3 is a section along the line 3-3 of Fi ur'e2,

Figure 4 a'section along the line t4 of Figure 2,

Figure 5 is-a'side elevation of a second percussion tool, and Figure 6 is a front'elevation of a third em-' bodiment of the invention.

In the case of the known and conventional percussion tools of the heavy duty type, such as are used in demolition and construction work and in mining operations, therehas been a justifiable, universal complaint that use of the devices worked unnecessary physical hardship on the operators due to excessive vibrations transmitted through the entire structures. This has been due to the fact that heretofore the tools have included fixed connections between the handles and the percussive means, as a result of which the vibratory motion attendant upon each stroke of AT ENT" OFFICE the air ,pistomis communicated through the frame members to the handles andthence-to the operator. The provision of spring-connections between handle and airham-mer has reduced in a minor degree only the unnecessary transmisthe only motion transmitted to the handle'means will be the minute longitudinal movement-"of the tool under impact of the percussive --member while reciprocal vibratory motion of the percussive member will-be, in so far as the operator is concerned, dissipated in the connection between percussive member and its'supp'orting frame,

Referring to Figures lto 4 of the drawings the numeral iii designates a frame member in the form of a'single rod bent inwardly at its bottom end, as at ll,"to forma part of a tool'retainer and bent outwardly at its upper end, as at l2, to accommodate ;the enlarged head Won the casing of apercussive member I4, withwhich it is connected. At its extreme upper end the frame 18 is provided with a handle I8, having a neck portion l9-to center the handlebver the percussive member. l4. The neck portion 19 may be connected to the upper end of frame rod ill by means of the bolts 2| or it may be an; integral part of the rod III, as preferred.

The connection between the percussive mem er it and rod 10 is reciprocal in character and in the formshown in Figures 1 too4,,.inclusive, the upper end I2 of rod i0 is flattenedout for a portion of its length (see Figures'l and 3) and provided with a longitudinally extending guideway 25 to slidably receive a flange 2B projecting laterally from head [3 on percussive member M. This slidable connection permits dissipation of the extreme vibration of the percussive member Ill when actuated by the usual compressed air stream.

The percussive member I4 is of conventional design and includes an air intake line 21 communicating with its upper end, the supply of air being controlled by a throttle valve for which a grip lever 28 is provided in handle l8. A flexible connection 29 between lever 28 and the throttle valve (not shown) is in keeping with the reciprocal connection between the percussive member 14 and rod ID. The percussive member l4 additionally has an exhaust port 30 and is chambered at its lower end in the usual way to receive a standard drill bit 3|. It will be appreciated, of course, that the present invention is not concerned with the internal construction of the percussive member and inasmuch as these devices are well known in the art, no details thereof are deemed necessary in the drawings or this description.

The lower end ll of rod 10, as stated, is bent inwardly to form aportion of a retainer for the bit 3!. In Figure 4 the particular shape of that part ofjshe retainer which is integral with rod III is shown to best advantage as conforming to the cross-section of one-half of the bit 3|, while a detachable complemental piece 32 forms the other half of the retainer means. The detachable piece -32 is secured to the end portion I I of rod 10 by conventional means such as the bolts 33 and nuts ;34. To provide a positive grip on bit 3| a re-, newable bushing 35 of rubber or like material is inserted between the bit 3| and the retainer :means, namely, the end H of rod l and the deatachable member 32.

In the form shown in Figure the percussive :member I 4 is supported for reciprocal vibratory movement on a frame 40 having substantially the same shape as rod ill in Figure 1 and provided 7 with the same drill bit retainer at its lower end including the detachable piece 32. In this form the connection between the percussive member l4 and frame 40 consists in a pin 42 projecting downwardly through a bore 43 in the inwardly bent upper end 44 of frame 40, which pin 42 is slidably received by a sleeve 45 formed integral with and projecting upwardly from head 45 of percussive member l4. Pin 42 may be adjusted relative to the sleeve 45 by means of a set screw 41 entering bore 43. A conventional handle 48 is formed on the upper end of pin 42 as a matter of simplifying the structure and the handle carries the usual throttle valve control lever 49.

In the form illustrated in Figure 6 the percussive member I 4 is supported on a U-shaped frame member 55 the legs of which are deformed at the point of their connection to provide one-half of a bit retainer 56, the other half of which may be a detachable piece 51 and, like the piece 32 of Figure 4, secured thereto by bolt 58. The legs of the frame member 55 are parallel for the greater portion of their length but flared outwardly at their upper ends, as at 59, to accommodate the enlarged head 60 of percussive member 14. The frame assembly is completed by a cross handle 6| having lugs 62 by which it is attached to the upper ends of the frame legs through the medium of cap screws 63. The slidable connection between percussive member 14 and frame 55 in the device of Figure 6 comprises guideways 68 in the upper ends of the two legs of the frame receiving 015- positely projecting flanges 69 on head 60.

In the three forms of the device shown in the drawings and described herein, it will be appreciated that the connections between the handle, frame and drill bit are rigid while the percussive member has a fioating" connection to the frame member. In this way the vibratory motion of the percussive member is dissipated in the sliding connection of hammer and frame and the only motion transmitted from the percussive member to the bit, and hence to the frame and handle assembly, will be the repeated impact of the percussive member on the drill. Such construction will not only avoid constant personal discomforture to the Operator but will provide a more positive control of the bit or other tool and enable the operator to operate the same with increased efficiency.

While I have shown and described but three forms of the invention it will be appreciated that the principles thereof may be incorporated in other devices, and I therefore desire full protection within the spirit and scope of the appended claims.

The invention claimed is:

1. A percussion tool of the shell mounted type comprising a frame member, a handle on the upper end of the frame member a member projecting downwardly from the handle portion of the frame, a positive grip tool retainer means carried by the lower end of the frame, a percussive means supported on a tool gripped by the retainer means, an upwardly projecting sleeve member on the percussive means to receive the member projecting downwardly from the handle portion of the frame.

2. A percussion tool of the shell mounted type comprising a frame member, a handle for the frame, a positive grip tool retainer carried by the frame, a percussive means slidably supported on the frame for operative contact with a tool gripped by the retainer means, a throttle valve carried by the handle means, and a flexible connection between the throttle valve and the percussive means. 7

VERNON L. PRICE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,190,387 Engels July 11, 1916 1,505,727 Prellwitz Aug. 19, 1924 1,511,566 Kollock Oct, 14, 1924 1,547,774 Prellwitz July 28, 1925 1,921,628 Maxwell Aug. 8, 1933 1,949,075 Hufiman Feb. 27, 1934 1,967,501 Curtis July 24, 1934 2,270,929 Bugg Jan, 27, 1942 

